Three large studies provide more support for a primarily plant-based diet. Two of the studies compared dietary protein from plants and animals and the third one compared dietary fats from plant or animal sources.

Comparing Protein Sources:
Researchers at Harvard monitored the records of more than 130,000 people for more than thirty years (JAMA Int Med, August 1, 2016), and found that:
• every three per cent increase in calories from plant protein, compared to animal protein, reduced risk of death during the study period by 10 per cent, and risk for death from heart disease by 12 percent
• eliminating unprocessed red meat dropped death risk by 12 per cent
• a 10 percent increase in animal protein was associated with a two per cent increased risk for death from all causes and an eight per cent increased risk for death from heart disease
• death rate rose markedly for those who smoked, drank excess alcohol, were obese or did not exercise
• regular eaters of red meat died earlier than those who regularly ate fish or chicken

Researchers from the Mayo Clinic in Arizona reviewed six studies involving more than 1.5 million people (Journal of the American Osteopathic Association, May, 2016), and found that:
• people who restrict red meat, fish and chicken for at least 17 years lived an average of 3.6 years longer than those who ate meat regularly
• eating red meat and processed meats is associated with earlier death, particularly from heart disease

Comparing Fat Sources:
Data from more than 126,000 participants followed for 32 years showed that increasing total fat intake is associated with decreasing risk of death during the study period (JAMA Intern Med, August 1, 2016;176(8):1134-1145). This may surprise you because previously researchers have associated increased dietary fat intake with increased heart attack risk. However, we now know that reducing fat intake by substituting sugars and other refined carbohydrates for fats actually increases heart attack risk. Heart attack risk appears to be increased primarily by eating too many foods and drinks with added sugars.

Saturated fats from animal sources and trans fats (partially hydrogenated vegetable oils) appear to increase heart attack risk, while polyunsaturated and monounsaturated fats decrease risk. The Nurses' Health Study and the Health Professionals Follow-up Study show that replacing five percent of saturated fat calories with polyunsaturated fats reduced death rate by 27 percent, and replacing five percent of saturated fat calories with monounsaturated fats reduced the death rate by 13 percent. Both omega-3s, found in deep water fish and many plant sources such as nuts, and omega-6 polyunsaturated fats found in most plants, are considered healthful. See my recent report on The Saturated Fat Debate.

All foods contain mixtures of different types of fats. Foods are classified by the dominant type of fat in them:
• Meat and poultry are classified as predominantly saturated fats
• Most plants are classified as predominantly polyunsaturated fats
• Olives, avocados, peanuts and many nuts and seeds are rich sources of monounsaturated fats

My Recommendations
Whether you are a vegan, a vegetarian or an omnivore, try to eat large amounts of unprocessed fruits, vegetables, whole grains, beans, seeds and nuts. I recommend that you restrict red and processed meats, sugar-added foods and all sugared drinks, including fruit juices and milk (which is high in the sugar lactose). If you are overweight, have high blood sugar levels or store fat primarily in your belly, you should also restrict all refined carbohydrates made from flour such as bakery products, pastas and most dry breakfast cereals.
Also see Anti-Inflammatory Foods and Pro-Inflammatory FoodsReduce Heart Attack Risk with Vegetable Oils

About the Author: Gabe Mirkin, MD

Sports medicine doctor, fitness guru and long-time radio host Gabe Mirkin, M.D., brings you news and tips for your healthful lifestyle. A practicing physician for more than 50 years and a radio talk show host for 25 years, Dr. Mirkin is a graduate of Harvard University and Baylor University College of Medicine. He is board-certified in four specialties: Sports Medicine, Allergy and Immunology, Pediatrics and Pediatric Immunology. The Dr. Mirkin Show, his call-in show on fitness and health, was syndicated in more than 120 cities.
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